The cam is a very critical part of an engines valvetrain. The cam is what lifts the valves into the combustion chamber allowing air to enter the cylinder. Cam profile selection is very critical on how an engine will run, and how log the cam will live. The cam along with the cylinder heads control how much air can enter the engine. The more air in the engine, the more power that can be made (within reason). This does not mean the most aggressive cam is the best one for you. You can get away with a fairly agressive cam on a carbureted vehicle. Be careful on a fuel injected engine as too much overlap will drop vacuum and will not allow the fuel injection to work correctly.
The Pontiac Fiero has some very interesting qualities, good and bad. It was built by GM in 1984 through 1988. The Pontiac Fiero was going to be a true GM sports car. It was a mid engine car as most exotic sports cars are. This means that the engine sits behind the driver. Having the engine behind the driver has many advantages in a sports car. This is why they are often used today in many kit car conversions. First the front to rear weight is usually close to 50/50 which would be a perfect balance.